I go to The cartridge man, think that's their new name. It used to be Rapid Refil. We've used them for yrs at the hospital and haven't had any problems and they stand behind thier products. Be careful, when you go to some of these places they aren't being refilled by people that have been taught properly plus they don't stand behind the refills if you have a problem. First check on the warranty offered and then the qualifications of employees who do it. At RR they already have the cartridges filled so you can get them off the shelf and its the same price rather you turn in your empties or not. It's still less than 1/2 of the cost any place else but is backed with a guarantee